In order to meet the demand for protection of interior trim of automobiles against deterioration, which has been increasing with the recent trend to luxury of the interior trim, and to reduce the load of air conditioning, a glass having ultraviolet and infrared radiation absorbing power has recently been proposed as an automotive window glass.
For example, a green tinted glass containing a relatively large amount of Fe.sub.2 O.sub.3 and having enhanced heat radiation and ultraviolet radiation absorbing power has been developed for automotive use.
In glasses having a bronze or brown tint, the ultraviolet radiation absorbing power thereof is enhanced by using CeO.sub.2 and TiO.sub.2 at a lower Fe.sub.2 O.sub.3 content than the green tinted glass. For example, the heat radiation absorbing glass having a bronze tint disclosed in JP-A-6-40741 (the term "JP-A" as use herein means an "unexamined published Japanese patent, application") comprises, in % by weight, basic glass components comprising 68 to 74% SiO.sub.2, 0.1 to 3% Al.sub.2 O.sub.3, 2 to 4.5% MgO, 8 to 11% CaO, 11.5 to 16% Na.sub.2 O, 0.5 to 3.0% K.sub.2 O, and 0.1 to 0.4% SO.sub.3, provided that the sum of SiO.sub.2 and Al.sub.2 O.sub.3 is 68 to 74%, the sum of CaO and MgO is 11 to 15%, and the sum of Na.sub.2 O and K.sub.2 O is 12 to 17%, and coloring components comprising 0.13 to 0.55% total iron oxide in terms of Fe.sub.2 O.sub.3, 0.2 to 0.6% CeO.sub.2, and 0.15 to 0.45% TiO.sub.2, and further comprises 0.3 to 14 ppm CoO and 5 to 20 ppm Se. This glass has a reduction rate (Fe.sup.2+ /Fe.sup.3+) of 17 to 55%.
The ultraviolet radiation absorbing colored glass disclosed in JP-A-6-345482 is a brown tinted glass which comprises, in % by weight, 65 to 75% SiO.sub.2, 0.1 to 5% Al.sub.2 O.sub.3, 1 to 6% MgO, 5 to 15% CaO, 10 to 18% Na.sub.2 O, 0 to 5% K.sub.2 O, 0.05 to 1.0SO.sub.3, 0.2 to 1.5% CeO.sub.2, 0 to 1.0% TiO.sub.2, 0 to 0.0015% CoO, 0.0002 to 0.0012% Se, and 0.2 to 0.4% Fe.sub.2 O.sub.3, wherein 3 to 15% of the total iron oxide in terms of Fe.sub.2 O.sub.3 is FeO.
The ultraviolet radiation absorbing colored glass disclosed in JP-A-6-345483 is a glass which comprises, in % by weight, 65 to 75% SiO.sub.2, 0.1 to 5% Al.sub.2 O.sub.3, 1 to 6% MgO, 5 to 15% CaO, 10 to 18% Na.sub.2 O, 0 to 5% K.sub.2 O, 0.05 to 1.0% SO.sub.3, 0.4 to 1.0% CeO.sub.2, 0 to 1.0% TiO.sub.2, 0.0018 to 0.0030% CoO, 0.0001 to 0.0010% Se, and 0.1 to 0.3% Fe.sub.2 O.sub.3, wherein 3 to 20% of the total iron oxide in terms of Fe.sub.2 O.sub.3 is FeO.
Furthermore, the gray glass composition disclosed in JF-A-8-48540 is a colored glass composition having a dull gray tint which comprises, in % by weight, 66 to 75% SiO.sub.2, 0 to 5% Al.sub.2 O.sub.3, 0 to 5% MgO, 5 to 15% CaO, 10 to 20% Na.sub.2 O, 0 to 5% K.sub.2 O, 0.0003 to 0.0050% CoO, 0.0001 to 0.0015% Se, and 0.30 to 0.70% Fe.sub.2 O.sub.3 (total iron oxide), with the FeO content being up to 0.21%, and which may further contain up to 2.0% CeO.sub.2, V.sub.2 O.sub.5, TiO.sub.2, and MoO.sub.3.
The above-described conventional ultraviolet and infrared radiation absorbing glasses have an ultraviolet radiation absorbing power imparted by Fe.sub.2 O.sub.3 CeO.sub.2, and TiO.sub.2, and by interactions among them. However, in the glasses having a bronze or neutral gray tint obtained by using the coloration of Se, the Fe.sub.2 O.sub.3 content must be reduced to a relatively low level in order to maintain the pink coloration of Se. Consequently, it has been difficult to achieve both a bronze or neutral gray tint and high ultraviolet radiation absorbing power.
That is, there has been the following problems. When the TiO.sub.2 content is increased, the glass tends to be yellowish. Even when the CeO.sub.2 content is increased, the coloration of Se is sometimes insufficient depending on the oxidation and reduction state of the glass, so that the ultraviolet radiation absorbing power is not effectively increased.
This kind of glasses further have a drawback that an increase in the proportion of FeO in total iron oxide tends to result in the above-described problems concerning color tint. In the case of ordinary glasses having a bronze or neutral gray tint and not having high ultraviolet radiation absorbing power, an increase in FeO proportion may impair the infrared radiation absorbing power thereof.
The present invention has been made in the light of the above-described problems associated with the conventional techniques.
An object of the present invention is to provide an ultraviolet and infrared radiation absorbing glass having a bronze or neutral gray tint and having especially high ultraviolet radiation absorbing power and satisfactory infrared radiation absorbing power.